You can never avoid RNG if a success rate is anything lower than 100%. If you're using CP touches instead of Hasty Touch, I understand what you are saying, but when it comes to recipes around your level it is very difficult to get quality to 100% using only CP touches.
A misconception I have realized while roaming about is what it means when you see something has a certain success rate. What needs to be understood is this rate is an individual case. It's the reason why if you buy a lotto ticket with 1/10 odds, buying 10 tickets doesn't guarantee you will win. You don't increase your odds to 100% by buying 10 tickets. Each individual ticket has a 10% chance of being a winner. RNG works very much the same way because well, it is the same thing.
When you see '80%' success rate, it doesn't mean 80% of your overall attempts are going to be successful. It means that this particular attempt has a 80% chance that it will succeed, and if it doesn't, your attempt landed in the 20% field and failed. This can happen EVERY attempt, and if you get an unlucky streak, it is just that: An unlucky streak.